The chiropractic subluxation is the essential basis of chiropractic theory. A true subluxation is a partial dislocation: chiropractors originally believed bones were actually out of place. When x-rays proved this was not true, they were forced to re-define the chiropractic subluxation as “a complex of functional and/or structural and/or pathological articular changes that compromise neural integrity and may influence organ system function and general health.” Yet most chiropractors are still telling patients their spine is out of alignment and they are going to fix it. Early chiropractors believed that 100% of disease was caused by subluxation. Today most chiropractors still claim that subluxations cause interference with the nervous system, leading to suboptimal health and causing disease.
What’s the evidence? In the 114 years since chiropractic began, the existence of chiropractic subluxations has never been objectively demonstrated. They have never been shown to cause interference with the nervous system. They have never been shown to cause disease. Critics of chiropractic have been pointing this out for decades, but now chiropractors themselves have come to the same conclusion.
In “An epidemiological examination of the subluxation construct using Hill’s criteria of causation” Timothy A. Mirtz, Lon Morgan, Lawrence H. Wyatt, and Leon Greene analyze the peer-reviewed chiropractic literature in the light of Hill’s criteria, the most commonly used model for evaluating whether a suspected cause is a real cause. They ask whether the evidence shows that chiropractic subluxations cause interference with the nervous system and whether they cause disease. The evidence fails to fulfill even a single one of Hill’s nine criteria of causation. They conclude:
There is a significant lack of evidence in the literature to fulfill Hill’s criteria of causation as regards chiropractic subluxation. No supportive evidence is found for the chiropractic subluxation being associated with any disease process or of creating suboptimal health conditions requiring intervention. Regardless of popular appeal this leaves the subluxation construct in the realm of unsupported speculation. This lack of supportive evidence suggests the subluxation construct has no valid clinical applicability. [emphasis added]
While some chiropractors have rejected the subluxation paradigm, it is supported by the major chiropractic organizations and schools and is considered essential by the great majority of practicing chiropractors. In two recent studies cited in the Mirtz et al. article, 98% of chiropractors believed that “most” or “many” diseases were caused by spinal misalignments and over 75% of chiropractors believed that subluxation was a significant contributing factor to 50% or more of visceral disorders (such as asthma and colic), an implausible idea that is not supported by any evidence whatsoever. Simon Singh was sued for saying so when he correctly referred to “wacky ideas” and “bogus treatments.”
When chiropractors use spinal manipulation therapy for symptomatic relief of mechanical low back pain, they are employing an evidence-based method also used by physical therapists, doctors of osteopathy, and others. When they do “chiropractic adjustments” to correct a “subluxation” for other conditions, especially for non-musculoskeletal conditions or “health maintenance,” they are employing a non-scientific belief system that is no longer viable.
As the authors of this paper indicate, the subluxation construct must go. And without the subluxation, the whole rationale for chiropractic collapses, leaving chiropractors no justifiable place in modern medical care except as competitors of physical therapists in providing treatment of certain musculoskeletal conditions.
The absence of publicity is astounding. This study has not even been noticed by the media. Where are the sensationalist journalists who usually exaggerate the news and make up provocative headlines? They could be trumpeting “Chiropractic Is Dead!” “Chiropractors Admit They Were Deluded by False Beliefs” “Simon Singh Vindicated: Chiropractic Really Is Bogus” and so on. Chiropractors demolishing the basis for chiropractic ought to be big news.
When the news finally gets out, I predict contorted efforts at damage control. Chiropractors will claim that it is not appropriate to apply the Hill criteria in this way, and that the criteria are not a valid test of causality. That’s a straw man: not even Hill suggested that the criteria were a definitive test. They are more of a guide to thinking about causality. Edzard Ernst, the world’s first professor of complementary and alternative medicine, finds them useful. He has recently applied Hill’s criteria to neck manipulation as a cause of stroke: he found that it fulfilled all but one of the criteria for causation. (Article pending publication). Chiropractors won’t like that either.
I predict the authors of this paper will be attacked as traitors by their colleagues. And I predict my own comments will be misinterpreted as some kind of personal vendetta and I will be called ugly names. I also predict that no one will dispassionately offer acceptable scientific evidence to contradict the findings of the paper (They can’t, because there isn’t any!). The first comment (and so far the only comment) on the Chiropractic and Osteopathywebsite offers no counter-evidence but rather calls for not letting evidence-based protocols overshadow clinical experience.(!) The Weekly Waluation of the Weasel Words of Woo could have a lot of fun translating that statement.
If chiropractors reject the conclusions of the Mirtz et al. paper, the burden of proof falls on them to show
- that the subluxation can be objectively demonstrated,
- that it does cause interference with the nervous system, and
- that it does cause disease.
They have failed to do so for 114 years.
Most chiropractic research falls under the category of Tooth Fairy Science. Instead of doing good basic research to examine the subluxation construct as a falsifiable hypothesis, they blindly forged ahead, implemented it for diagnosis and treatment, and studied various aspects of its clinical use.
The chiropractic emperor has no clothes, and now even some chiropractors have realized that. This study should mark the beginning of the end for chiropractic, but it won’t. Superstition never dies, particularly when it is essential to livelihood.
This article was originally published in the Science-Based Medicine Blog.